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do_process_vm_read_writev(): access local vector buffer using kernel virtual, PF if necessary

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Change-Id: Ic90dca79e32d4151f585a5cbd5b2c7710534db0e
This commit is contained in:
Balazs Gerofi
2019-09-28 08:14:04 +09:00
committed by Masamichi Takagi
parent 1db00ebc04
commit 5b26fe2956
1 changed files with 55 additions and 12 deletions
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67
arch/arm64/kernel/syscall.c
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@ -2140,10 +2140,10 @@ int do_process_vm_read_writev(int pid,
struct process *rproc;
struct process *lproc = lthread->proc;
struct process_vm *rvm = NULL;
unsigned long rphys;
unsigned long rpage_left;
unsigned long psize;
void *rva;
unsigned long lphys, rphys;
unsigned long lpage_left, rpage_left;
unsigned long lpsize, rpsize;
void *rva, *lva;
struct vm_range *range;
struct mcs_rwlock_node_irqsave lock;
struct mcs_rwlock_node update_lock;
@ -2337,10 +2337,53 @@ pri_out:
to_copy = remote_iov[ri].iov_len - roff;
}
retry_lookup:
retry_llookup:
/* Figure out local physical */
/* TODO: remember page and do this only if necessary */
ret = ihk_mc_pt_virt_to_phys_size(lthread->vm->address_space->page_table,
local_iov[li].iov_base + loff, &lphys, &lpsize);
if (ret) {
uint64_t reason = PF_POPULATE | PF_WRITE | PF_USER;
void *addr;
if (faulted) {
ret = -EFAULT;
goto out;
}
/* Fault in pages */
for (addr = (void *)
(((unsigned long)local_iov[li].iov_base + loff)
& PAGE_MASK);
addr < (local_iov[li].iov_base + loff + to_copy);
addr += PAGE_SIZE) {
ret = page_fault_process_vm(lthread->vm, addr, reason);
if (ret) {
ret = -EFAULT;
goto out;
}
}
faulted = 1;
goto retry_llookup;
}
lpage_left = ((((unsigned long)local_iov[li].iov_base + loff +
lpsize) & ~(lpsize - 1)) -
((unsigned long)local_iov[li].iov_base + loff));
if (lpage_left < to_copy) {
to_copy = lpage_left;
}
lva = phys_to_virt(lphys);
retry_rlookup:
/* Figure out remote physical */
/* TODO: remember page and do this only if necessary */
ret = ihk_mc_pt_virt_to_phys_size(rvm->address_space->page_table,
remote_iov[ri].iov_base + roff, &rphys, &psize);
remote_iov[ri].iov_base + roff, &rphys, &rpsize);
if (ret) {
uint64_t reason = PF_POPULATE | PF_WRITE | PF_USER;
@ -2366,11 +2409,11 @@ retry_lookup:
}
faulted = 1;
goto retry_lookup;
goto retry_rlookup;
}
rpage_left = ((((unsigned long)remote_iov[ri].iov_base + roff +
psize) & ~(psize - 1)) -
rpsize) & ~(rpsize - 1)) -
((unsigned long)remote_iov[ri].iov_base + roff));
if (rpage_left < to_copy) {
to_copy = rpage_left;
@ -2379,16 +2422,16 @@ retry_lookup:
rva = phys_to_virt(rphys);
fast_memcpy(
(op == PROCESS_VM_READ) ? local_iov[li].iov_base + loff : rva,
(op == PROCESS_VM_READ) ? rva : local_iov[li].iov_base + loff,
(op == PROCESS_VM_READ) ? lva : rva,
(op == PROCESS_VM_READ) ? rva : lva,
to_copy);
copied += to_copy;
dkprintf("local_iov[%d]: 0x%lx %s remote_iov[%d]: 0x%lx, %lu copied, psize: %lu, rpage_left: %lu\n",
dkprintf("local_iov[%d]: 0x%lx %s remote_iov[%d]: 0x%lx, %lu copied, rpsize: %lu, rpage_left: %lu\n",
li, local_iov[li].iov_base + loff,
(op == PROCESS_VM_READ) ? "<-" : "->",
ri, remote_iov[ri].iov_base + roff, to_copy,
psize, rpage_left);
rpsize, rpage_left);
loff += to_copy;
roff += to_copy;